sed匹配问题

borefo

1. 
   
2. linux-svy2:/opt/sed # cat example
   
3. The honeysuckle band played all night long for only $90.
   
4. It was an evening of splendid music and company.
   
5. Too of bad the disco floor fell through at 23:00.
   
6. The local nurse Miss P.Neave was in attendance.
   

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执行下面为什么会有下面结果？

1. 
   
2. linux-svy2:/opt/sed # sed -n '1, /\$90/p' example
   
3. The honeysuckle band played all night long for only $90.
   
4. It was an evening of splendid music and company.
   
5. Too of bad the disco floor fell through at 23:00.
   
6. The local nurse Miss P.Neave was in attendance.
   

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按照我的理解，应该只打印第一行，为什么全部打印出来了呢？

lkk2003rty

因为/\$90/p
但是最后两行  没有理由啊。。。不懂。。。。

shileiadmin

你要的结果是这个
sed -n '1,/\$90$/p' example

iori809

回复 1# borefo


    是这样的~你要搜索第一行至 那个表达式的行
Sed直到最后一行都没找到，所以就一直打印
只要第一个条件满足就为TRUE

lkk2003rty

再仔细看了看  兰州两次的example文件内容不一样吧。。。。

expert1

borefo

再仔细看了看  兰州两次的example文件内容不一样吧。。。。
lkk2003rty 发表于 2010-07-19 15:27

不好意思，文本确实发错了，现在更改过来了

blackold

用awk吧，结果是你想要的。

sosodream

If the second address is a REGEXP, then checking for the ending
match will start with the line _following_ the line which matched the
first address: a range will always span at least two lines (except of
course if the input stream ends).

（节选info sed)

当第二段地址为正则时，第二段地址的匹配从第一个地址生效“下一行”为起始

用楼主的例子还说，就是，1匹配了第一行，但/\$90/是从第二行开始匹配的

解决的方法：
1改成0


说明：
`0,/REGEXP/'
     A line number of `0' can be used in an address specification like
     `0,/REGEXP/' so that `sed' will try to match REGEXP in the first
     input line too.  In other words, `0,/REGEXP/' is similar to
     `1,/REGEXP/', except that if ADDR2 matches the very first line of
     input the `0,/REGEXP/' form will consider it to end the range,
     whereas the `1,/REGEXP/' form will match the beginning of its
     range and hence make the range span up to the _second_ occurrence
     of the regular expression.

jy02107028

试了一下，因为你的第1行和$90是同一行，第1行是肯定要打出来的，而$90是从第2行开始查找，结果直到最后也没找到，因此全部打出来了